Organic electroluminescence device

Abstract

An organic electroluminescence device including a first electrode; a hole transport region on the first electrode; a light emitting layer on the hole transport region; an electron transport region on the light emitting layer; and a second electrode on the electron transport region, wherein the light emitting layer includes a first compound satisfying Formula 1 below and a second compound satisfying Formula 2 below, and the first compound has a full width at half maximum of 60 nm or less: V 2> V 1  [Formula 1] K 1>1.1× K 2.  [Formula 2]

What is claimed is: 
     
         1 . An organic electroluminescence device, comprising:
 a first electrode;   a hole transport region provided on the first electrode;   a light emitting layer provided on the hole transport region;   an electron transport region provided on the light emitting layer; and   a second electrode provided on the electron transport region,   wherein the light emitting layer includes a first compound satisfying Formula 1 below and a second compound satisfying Formula 2 below, and the first compound has a full width at half maximum of 60 nm or less:
     V 2> V 1  [Formula 1]
 
   wherein, in Formula 1,   V1 is a sum of non-radiative transition rates transitioning from an n th  triplet excited state to a lower order triplet excited state including the lowest triplet excited state, and   V2 is a reverse intersystem transition rate transitioning from an n th  triplet excited state to a singlet excited state adjacent to the n th  triplet excited state, where n is an integer of 2 or greater; and,
     K 1>1.1× K 2  [Formula 2]
 
   wherein, in Formula 2,   K1 is an energy level of a lowest singlet excited state of the second compound, and   K2 is an energy level of a lowest triplet excited state of the second compound.   
     
     
         2 . The organic electroluminescence device as claimed in  claim 1 , wherein:
 the light emitting layer includes a host and a dopant,   the host includes the first compound, and   the dopant includes the second compound.   
     
     
         3 . The organic electroluminescence device as claimed in  claim 2 , wherein the dopant is a fluorescent dopant. 
     
     
         4 . The organic electroluminescence device as claimed in  claim 2 , wherein a weight percentage of the dopant based on a total weight of the host and the dopant is 0.01 wt % to 10 wt %. 
     
     
         5 . The organic electroluminescence device as claimed in  claim 2 , wherein:
 the host includes a first host and a second host,   the first host is the first compound, and   an energy level of the lowest triplet excited state of the second host is higher than an energy level of the lowest singlet excited state of the first compound.   
     
     
         6 . The organic electroluminescence device as claimed in  claim 2 , wherein:
 the host includes a first host and a second host,   the first host is the first compound, and   an energy level of the lowest singlet excited state of the second host is lower than an energy level of the lowest singlet excited state of the first compound.   
     
     
         7 . The organic electroluminescence device as claimed in  claim 1 , wherein the first compound satisfies Formula 1-1 below:
     V 2≥0.1× V 1  [Formula 1-1]
   wherein, in Formula 1-1, V1 and V2 are defined the same as those of Formula 1.   
     
     
         8 . The organic electroluminescence device as claimed in  claim 1 , wherein V1 is 1×10 9  s −1  or less.